A cannon of mass 5.24 x 103 kilogram is rigidly bolted to the earth therefore it can recoil only by a negligible amount. The cannon fires a 78.6 kilogram shell horizontally with an initial velocity of 512 m/s. Assume the cannon is then unbolted from the earth, and no external force hinders its recoil. Find the velocity of a shell fired from these loose cannon? (Hint: In both cases assume that the burning gunpowder imparts the same kinetic energy to the system.)